Causes of Dry Mouth (Xerostomia)

Dry mouth (also known as xerostomia) is a condition that results from decreased production of saliva. While saliva moistens and cleans our mouths, it also aids in food digestion and helps control the bacteria and fungi that can cause infections and tooth decay.

At times, dry mouth can make it difficult to eat and speak. Extreme dry mouth, without treatment, can also result in salivary gland dysfunction, causing significant mouth and throat disorders.

There are several causes of dry mouth, also called xerostomia. These include:

Dry Mouth
Credit: nidcr


There are over 1,800 medications, both prescription and over-the-counter, that have a side effect of dry mouth. Some of the most commonly prescribed include:

  • ADHD medications (methylphenidate and amphetamines)
  • Narcotic pain relievers
  • SSRI antidepressants
  • Tricyclic antidepressants
  • Bupropion (and other NRI antidepressants)
  • Sleep medications (like Ambien and Lunesta)
  • Oxybutynin (for bladder control or incontinence)
  • Antipsychotics
  • Muscle relaxants (cyclobenzaprine)
  • Clonidine
  • Everyday medicines, such as cold remedies and antihistamines


While dry mouth tends to be more common in the elderly, it is not necessarily due to their age, but rather the fact that this population tends to take several medications. Half of all Americans aged 60 years or older take three or more prescription medications on a regular basis. Older people are also more likely to be affected by cancer and Sjögren’s syndrome, both of which cause dry mouth.

Sjögren’s Syndrome

Dry mouth is one of the more prominent symptoms of Sjögren’s syndrome. This disease affects the body’s immune system and attacks the tear and salivary glands. Females are more likely to suffer from this chronic condition as 90% of people with the disease are women.


One of the most common oral health problems of diabetics is dry mouth because diabetics have an increased risk of dehydration due to higher blood glucose levels. While thirst may be the first indicator people recognize, dry mouth and dry eyes are also a main symptom of dehydration. Learn how to treat dry mouth from diabetes.

Cancer and Treatment

Chemotherapy or radiation treatments can be damaging to the salivary glands of neck and head cancer patients specifically. Although some may regain partial salivary production after the first year of their treatment, many will continue to suffer from long-term dry mouth symptoms, especially if radiation was directed at their salivary glands.

Parkinson's disease

Some people with Parkinson’s disease experience dry mouth because they swallow repeatedly, which uses up the saliva that is needed to be comfortable. Dry mouth may also be caused by some of the medications for Parkinson’s disease, particularly anticholinergic medications.

Cannabis Use

Anyone who’s used marijuana has experienced the frustration of dry mouth. Commonly known as “cotton mouth,” dry mouth from marijuana is caused by chemical compounds called cannabinoids that block the production of saliva. Researchers now know that imbibing marijuana in any form—not just smoking it—leads to xerostomia.


For more information on dry mouth, how to treat it, and associated symptoms, please visit our dry mouth page.

Dry mouth, caused by many of these diseases, can be relieved using by using Xylimelts, a dentist approved dry mouth product designed for effective, long lasting results